Electron avalanche putative energy field analyzer

Abstract

A device and method of detecting and analyzing a vital field places an avalanche diode in the path of vital waves in the vital field. The vital waves interfere with the electron avalanche process in the avalanche diode. Control circuitry and an avalanche initiator cause electron avalanches at a known sampling frequency. The interference from the vital waves produces a beat frequency that is output from the avalanche diode. By adjusting the sampling rate by a known amount, a second beat frequency is produced and the beat frequency shift is used to determine the input frequency of the vital waves. The vital waves are very weak and produce frequencies into the terahertz range, so that the input frequency is undersampled by the device. Further, high sensitivity is required and a circuit design is implemented to maximize sensitivity while minimizing noise and other interference that is common to avalanche diode operation.

1. A device for detecting and analyzing vital fields, the device comprising:
 a) control circuitry configured to generate a first control signal at a first sampling frequency and a second control signal at a second sampling frequency different from the first sampling frequency; 
 b) a detector in electrical communication with the control circuitry, the detector comprising:
 i. an avalanche diode having an active region on which vital waves from the vital field are incident; 
 ii. an avalanche initiator configured to provide energy to the avalanche diode, the energy generating seed electrons for electron avalanches; 
 iii. a capacitor coupled to the avalanche diode's cathode and configured to periodically apply a low voltage to the cathode; and 
 iv. electromagnetic shielding substantially enclosing the avalanche diode and the avalanche initiator such that the electromagnetic shielding prevents unwanted electromagnetic interference with the electron avalanches but allows the vital waves to pass; and 
 
 c) signal processing circuitry in electrical communication with the detector; 
 wherein: 
 a) the control circuitry sends the first control signal to the detector; 
 b) the first control signal causes the capacitor to modulate high gain operation of the avalanche diode at the first sampling frequency by applying the low voltage to the cathode at the first sampling frequency; 
 c) an input frequency from the vital waves mixes with a harmonic of the first sampling frequency in the active region of the avalanche diode during high gain operation of the avalanche diode, generating a first mixed signal having a first beat frequency; 
 d) the avalanche diode sends the first mixed signal to the signal processing circuitry; 
 e) the control circuitry sends the second control signal to the detector; 
 f) the second control signal causes the capacitor to modulate high gain operation of the avalanche diode at the second sampling frequency by applying the low voltage to the cathode at the second sampling frequency; 
 g) the input frequency from the vital waves mixes with a harmonic of the second sampling frequency in the active region of the avalanche diode during high gain operation of the avalanche diode, generating a second mixed signal having a second beat frequency; 
 h) the avalanche diode sends the second mixed signal to the signal processing circuitry; and 
 i) the signal processing circuitry determines the input frequency from the vital waves using the first and second beat frequencies. 
 
     
     
       2. The device of  claim 1  wherein the avalanche initiator constantly provides energy to the avalanche diode, and wherein the detector further comprises a level control circuit configured to provide an adjustable current to the avalanche initiator. 
     
     
       3. The device of  claim 2  wherein the detector further comprises a monitoring diode configured to monitor the amount of energy output by the avalanche initiator and to signal the level control circuit if the amount of energy is out of a desired range. 
     
     
       4. The device of  claim 1  wherein the detector further comprises a focusing horn connected to the electromagnetic shielding and positioned to concentrate the vital waves into the active region of the avalanche diode. 
     
     
       5. The device of  claim 1  wherein the detector further comprises a short-circuit lowpass filter configured to make the first and second mixed signals baseband signals. 
     
     
       6. The device of  claim 1  wherein the signal processing circuitry comprises a Fourier transform computer configured to extract frequency data from the first and second mixed signals. 
     
     
       7. The device of  claim 6  wherein the signal processing circuitry further comprises a frequency converter configured to simplify the extraction of frequency data by the Fourier transform computer. 
     
     
       8. The device of  claim 6  wherein the signal processing circuitry further comprises a screen for displaying frequency data extracted by the Fourier transform computer. 
     
     
       9. A device for detecting and analyzing vital fields, the device comprising:
 a) control circuitry configured to generate a control signal at a desired sampling frequency; 
 b) a detector in electrical communication with the control circuitry, the detector comprising:
 i. a silicon avalanche photodiode having an active region on which vital waves from the vital field are incident; 
 ii. a voltage source configured to supply a substantially constant voltage to the avalanche photodiode's cathode; 
 iii. a pulse capacitor configured to apply a low voltage to the avalanche photodiode's cathode at the sampling frequency, such that the sum of the substantially constant voltage and the low voltage is slightly below the avalanche photodiode's breakdown voltage and places the avalanche photodiode into a high gain period; 
 iv. a silicon vertical cavity surface emission laser (“VCSEL”) configured to send substantially constant laser energy into the avalanche photodiode, wherein the laser energy generates a low average number of seed electrons for an electron avalanche; 
 v. an automatic level control circuit configured to supply the VCSEL with an adjustable current; 
 vi. a monitoring diode that monitors the amount of laser energy output by the VCSEL and signals the automatic level control circuit if the amount is outside a desired range; 
 vii. a Faraday cage substantially enclosing at least the avalanche photodiode, the VCSEL, and the monitoring diode; 
 viii.a brass focusing horn connected to the Faraday cage and having an opening inside the Faraday cage, the brass focusing horn positioned to concentrate the vital waves into the active region of the avalanche photodiode so that an input frequency from the vital waves mixes with a harmonic of the sampling frequency in the active region of the avalanche diode during the high gain period, generating a mixed signal having a beat frequency; 
 ix. an opaque dielectric material covering the focusing horn's opening inside the Faraday cage; and 
 x. a short-circuit lowpass filter configured to receive the mixed signal from the avalanche photodiode and short-circuit frequencies in the mixed signal that are at or higher than half the sampling frequency; and 
 
 c) signal processing circuitry in electrical communication with the detector, the signal processing circuitry comprising:
 i. a baseband amplifier that receives the mixed signal from the short-circuit lowpass filter and amplifies the mixed signal; 
 ii. a baseband lowpass filter that receives the mixed signal from the baseband amplifier and filters noise caused by amplification; 
 iii. an analog-to-digital converter that receives the mixed signal from the baseband lowpass filter and converts it from analog to digital; and 
 iv. a Fourier transform computer that receives the mixed signal from the analog-to-digital converter, extracts frequency data including the beat frequency from the mixed signal, and processes the frequency data to obtain spectral data about the vital waves. 
 
 
     
     
       10. A method of detecting and analyzing a vital field, the method comprising:
 a) generating a first control signal having a first sampling frequency and a second control signal having a second sampling frequency; 
 b) positioning an avalanche diode in the vital field so that vital waves from the vital field are incident upon the avalanche diode's active region; 
 c) using the first control signal to generate a first mixed signal having a first beat frequency by:
 i. sending the first control signal to the avalanche diode so that the gain of the avalanche diode is modulated at the first sampling frequency; and 
 ii. initiating electron avalanches in the avalanche diode using energy provided by an avalanche initiator so that the modulated gain generates a harmonic of the first sampling frequency that mixes with an input frequency of the vital waves to cause the avalanche diode to output the first mixed signal; 
 
 d) using the second control signal to generate a second mixed signal having a second beat frequency by:
 i. sending the second control signal to the avalanche diode so that the gain of the avalance diode is modulated at the second sampling frequency; and 
 ii. initiating electron avalanches in the avalanche diode using energy provided by an avalanche initiator so that the modulated gain generates a harmonic of the second sampling frequency that mixes with the input frequency of the vital waves to cause the avalanche diode to output the second mixed signal; and 
 
 e) determining the input frequency of the vital waves by:
 i. finding the beat frequency shift between the first beat frequency and the second beat frequency; 
 ii. using the beat frequency shift to determine the frequency of the harmonic of the first sampling frequency that mixed with the input frequency; and 
 iii. adding the first beat frequency to the frequency of the harmonic of the first sampling frequency.